This invention relates to a scribe process and a scribe device for forming a scribe line on a surface of a workpiece of a hard material such as a sheet glass, or the like.
In general, in case a workpiece such as a sheet glass or the like is caused to be fracture, a scribe line is preliminarily formed on the surface of the workpiece and the workpiece is caused to be fracture along this scribe line. A conventional scribe device used for forming such a scribe line is disclosed, for example, in Japanese Utility Model Unexamined Publication No. Hei 1-110234. Specifically, as shown in FIGS. 22A and 22B, the conventional scribe device comprises a disc-shaped cutter 90 (abutment member) with a sharpened peripheral edge, a holder 91 rotatably supporting the cutter 90, and a pressing/moving mechanism (not shown) for pressing the cutter 90 against a surface of a sheet glass 100 (workpiece) through the holder 91 and moving the cutter 90 along the surface of the sheet glass 100.
A scribe line 105 is formed by moving the cutter 90 pressed against the sheet glass 100 as described above. The scribe line 105 includes, as shown in FIG. 22A, an edge entry portion 105a, a rib mark 105b, and a vertical crack 105c. In order to facilitate a fracture of the sheet glass 100, it is necessary to form the vertical crack 105c deeply. For this purpose, it suffices that the force for pressing the cutter 90 against the sheet glass 100 is increased. However, if the cutter 90 is pressed against the sheet glass 100 with an increased pressing force, there is a possibility that the scribe line 105 including not only the vertical crack 105c but also a horizontal crack 106 extending leftwardly and rightwardly from the scribe line 105 tend to occur as shown in FIG. 22B, thus unfavorably resulting in a cut, a peel-off, or the like formed in the vicinity of the scribe line 105 due to the horizontal crack 106.
In contrast, if the force for pressing the cutter 90 against the sheet glass 100 is decreased, the horizontal crack 106 does not occur but a sufficiently large depth of the vertical crack 105c becomes unobtainable. This means that the intended favorable fracture of the sheet glass 100 is unobtainable.
It is an object of the present invention to provide a scribe device capable of forming a deep and beautiful scribe line.
The subject matter of the present invention resides in a scribe process for scribing a surface of a workpiece by applying vibrations to the workpiece while pressing an abutment member against the surface of the workpiece.
In a device for carrying our this process, a holder is supported by a body such that the holder can slightly slide in a direction of a slide axis which intersects a surface of a workpiece. Retainer portions spaced apart in the direction of the slide axis are each formed on the body and the holder, respectively. A vibratory actuator is sandwiched between the retainer portion of the body and the retainer portion of the holder. The holder holds an abutment member, The holder is biased by a biasing member such that the retainer portion of the holder is pressed against the vibratory actuator. The vibratory actuator renders vibrations in the direction of the slide axis to the holder. The abutment member transmits the vibrations from the holder to the workpiece. When the body or the workpiece is moved, either manually or by a moving mechanism, relative to each other in that state, a scribe line is formed.
In a modified device, the body is attached with an elastic arm and an abutment member is attached to a distal end portion of the elastic arm. Vibrations of a vibratory actuator are transmitted to the abutment member through the elastic arm.